1. Technical Field
The present invention relates to a digital inkjet printing method capable of imparting a transparent color to a UV-curable transparent ink, so as to improve an added value and market competitiveness of a printed product.
2. Related Art
A UV inkjet printer can print on various objects to be printed of different materials or thicknesses, so that a fast printing speed is provided and stable and consistent print quality is achieved, and moreover, with reliable performance of the UV inkjet printer, printing can be rapidly completed because the work for fabricating a color separation screen is omitted and the time is saved for a user. Therefore, UV inkjet printers are widely used in professional and commercial outputs such as advertisements, posters, and high-quality art reproduction.
A commercially available UV inkjet printer at present mainly includes an inkjet module capable of being controlled to move to and fro and disposed on a sliding platform of a machine, a plurality of ink cartridges disposed above the inkjet module, and a plurality of inkjet heads corresponding to the ink cartridges and disposed below the inkjet module. A jet nozzle at the bottom of the inkjet head jets ink on an object to be printed, and then a UV lamp disposed at a side of the inkjet module projects light on the ink that has been jetted and printed on the object to be printed, so that the ink is rapidly cured and solidified. During printing on an object to be printed, conventionally a unidirectional single printing mode or a bi-directional back and forth printing mode is adopted to print each area to be printed of the object to be printed, so as to shorten the time of printing. If a surface of the object to be printed is required to have a transparent effect after printing is completed, when printing of a pattern in each area to be printed of the object to be printed is completed, a layer of a transparent ink is generally jetted and the transparent ink jetted on the area to be printed is immediately cured by using a UV lamp, so as to form a transparent layer on the pattern in the area to be printed, thereby forming a transparent three-dimensional effect on the surface of a printed product of the processed object.
However, in the manner described above, a transparent effect is merely formed on a color pattern. Therefore, it is a research direction of the inventor to make a transparent ink to exhibit a slight color effect to improve an added value and market competitiveness of a printed product.